scala - Using the kronecker product on complex matrices with scalaNLP breeze -

i had piece of code:

def this(vectors: list[densevector[double]]) {     this(vectors.length)     var resultvector = vectors.head     (vector <- vectors) {         resultvector = kron(resultvector.todensematrix, vector.todensematrix).todensevector     }     _vector = resultvector } 

it worked way wanted work. problem needed complex values in stead of doubles. after importing breeze.math.complex, changed code to:

def this(vectors: list[densevector[complex]]) {     this(vectors.length)     var resultvector = vectors.head     (vector <- vectors) {        resultvector = kron(resultvector.todensematrix, vector.todensematrix).todensevector     }     _vector = resultvector } 

this results errors:

error:(42, 26) not find implicit value parameter impl: breeze.linalg.kron.impl2[breeze.linalg.densematrix[breeze.math.complex],breeze.linalg.densematrix[breeze.math.complex],vr]       resultvector = kron(resultvector.todensematrix, vector.todensematrix).todensevector                          ^  error:(42, 26) not enough arguments method apply: (implicit impl: breeze.linalg.kron.impl2[breeze.linalg.densematrix[breeze.math.complex],breeze.linalg.densematrix[breeze.math.complex],vr])vr in trait ufunc. unspecified value parameter impl.       resultvector = kron(resultvector.todensematrix, vector.todensematrix).todensevector                          ^ 

is bug or forgetting something?

i found problem in following way:

1. i first rewrote function use less matrix conversions
2. as there problem implicit impl variable of kron, rewrote function call explicitly state variable use use

.

def this(vectors: list[densevector[complex]]) {     this(vectors.length)     var resultmatrix = vectors.head.todensematrix     (i <- 1 until vectors.length) {          resultmatrix = kron(resultmatrix, vectors(i).todensematrix)(kron.krondm_m[complex, complex, densematrix[complex], complex])     }     _vector = resultmatrix.todensevector } 

this showed me there no scalarmulop v2, m, densematrix[rv] m matrix[v1], v1 , v2 input types , rv output type of scalarmulop

digging through source code of breeze found in densematrixops there implicit scalarmulop above types if v1, v2 , rv of type int, long, float , double. copying function , making specific complex numbers, able kronecker product work. remove explicit use of (kron.krondm_m[complex, complex, densematrix[complex], complex]). scalarmulop function in question is:

implicit def s_dm_op_complex_opmulscalar(implicit op: opmulscalar.impl2[complex, complex, complex]):   opmulscalar.impl2[complex, densematrix[complex], densematrix[complex]] =      new opmulscalar.impl2[complex, densematrix[complex], densematrix[complex]] {       def apply(b: complex, a: densematrix[complex]): densematrix[complex] = {         val res: densematrix[complex] = densematrix.zeros[complex](a.rows, a.cols)         val resd: array[complex] = res.data         val ad: array[complex] = a.data         var c = 0          var off = 0         while (c < a.cols) {           var r = 0           while (r < a.rows) {             resd(off) = op(b, ad(a.linearindex(r, c)))             r += 1             off += 1           }           c += 1         }          res       }        implicitly[binaryregistry[complex, matrix[complex], opmulscalar.type, matrix[complex]]].register(this)     }